How will the boxes be affixed? If the boxes you have aren't designed to attach to the metal stud, you may have trouble. If they are the "remodel" type box that clamps to the drywall with 2 plastic tabs, you'd have to drywall first, cut the hole, find the cable(s), insert the box in the hole and secure, then perform the wiring connections. Seems like a hassle to me.

They are not the remodel boxes. Some are the blue adjustable boxes with the metal bracket on the side to mount to a stud. The others are the blue boxes with the blue plastic bracket. I don't know if they are good for metal studs though.